Scientific Method activity Essay Example for Free

Scientific Method activity Essay Complete the Scientific Method activity on the student website. Write a 350 word paper on the scientific method. Include the following: Describe how you applied the steps of the scientific method in the activity. Describe a real-life problem where you have or could have used the scientific method. Include the steps involved in solving the problem. I completed both the tomato growing and the car starting exercises. I first identified the problem. The tomato plants were not producing as many tomatoes as they had in the past, the car would not start. I then questioned why the plants were not producing and why the car would not start. I looked at my options for the tomato plants. First I thought that the plants needed more water. I tried this theory and was wrong. I went back to my options on how to solve the problem. Next I thought maybe the soil needed more nutrients. Once again I was wrong. Last, I tried the hypothesis of the plants needing more sun, and placed the tomato plants in a green house. This experiment worked and the plants began producing more tomatoes. With the car I had options of car battery or fluids. I tried the car battery thinking that the cables may be loose. I was wrong. I tired changing the spark plugs and fuses. I was wrong. I went back to the car battery and tried a charge. Once again I was wrong. With my only option now being the fluid I tried adding gasoline to the car and the car started. Through both experiments I observed the problem, questioned it, came up with one hypothesis, made a prediction, tired an experiment, came up with results and when I found my hypothesis was incorrect I came up with another and proceeded through the steps until my experiment was successful. Each time we do an experiment we get results. When our results aren’t working to our benefit we have to rethink. A new hypothesis must be made with the prediction of correct results. In both cases with the tomatoes and the car we learn from trial and error. A real life situation where I could have used the scientific method is for example; my stomach hurts. I have observed the situation. Why does my stomach hurt? Hypothesis – I have not been getting all of my daily nutrients. Prediction- My stomach hurts because I have not been eating right. Experiment- I try eating daily recommended servings of grains,  protein, veggies, fruits and milk products. Result- My stomach no longer hurts. I deal with this regularly because I do not eat right. I toy with eating different things, adding or taking away from my daily diet. I use the scientific method on a daily basis.

The Atlantic Charter Churchill And Roosevelt Legendary Meeting History Essay

The Atlantic Charter Churchill And Roosevelt Legendary Meeting History Essay August 8, 1941, the crew of Britains newest battleship HMS Prince of Wales was cleaving her way at top-speed through the unrelenting heavy seas of the Atlantic to Placentia Bay, Newfoundland. Onboard this ship is British Prime Minister Sir Winston Churchill, who had made the voyage across the Atlantic where President Roosevelt eagerly awaited the onset of discussions fateful to the outcome of the Second World War. On August 9, 1941, President Roosevelt and Prime Minister Churchill met onboard the American cruiser U.S.S. Augusta anchored off the coast of Newfoundland. The discussion between the two leaders at the meeting would result in a joint declaration called the Atlantic Charter. It promptly created a critical alliance which supported Britain in its fight against the Nazi Regime. Subsequently the agreement established post-war goals for World War II and laid the groundwork for future international peacekeeping organizations. Two years prior to the beginning of World War II in the spring of 1938, German speakers living in the Sudetenland region of Czechoslovakia began favoring for closer ties with Germany. Hitler began to support those requests and favored reclaiming the Sudetenland. He had recently annexed Austria into Germany and the conquest of Czechoslovakia was the next step in his plan of creating a greater Germany (Sep 30, 1938). Prime Minister Neville Chamberlain was intent on averting war, although the Czechoslovak government hoped that Britain and France would offer assistance in the event of a German invasion (Sep 30, 1938). Chamberlain traveled twice to Germany to offer Hitler favorable agreements, but the German chancellor kept increasing his demands (Sep 30, 1938). International tension increased when Hitler began demanding the Sudetenland in Czechoslovakia be under the control of the German government. In an attempt to resolve the crisis, Chamberlain met with the leaders of Germany, France, and Italy in Munich to discuss the terms of handling the Sudetenland. Within the early morning hours of September 30, 1938 Adolf Hitler of Germany, Benito Mussolini of Italy, Èduoard Daladier of France, and Neville Chamberlain of Britain signed the Munich Pact, which sealed the fate of Czechoslovakia, virtually handing it over to Germany in the name of peace (Sep 30, 1938). The Munich Pact sacrificed the autonomy of Czechoslovakia on the pedestal of a very short peace term (Sep 30, 1938). The peace of the world only lasted eleven months before Hitler seized the rest of Czechoslovakia in March of 1939 (Friedrich). In response to Hitlers violation of the Munich Agreement, Britain signed with Poland the Polish-British Common Defense Pact, which guaranteed the integrity of the Polish state. Chamberlains decision to sign Poland after the dismemberment of the Czechoslovak state meant Britain, along with France were committed to protecting a nation where they had no common borders (Invasion of Poland). Reacting to the Anglo-Polish alliance, Hitler negotiated the German-Soviet Pact of August 1939, which made Poland partitioned between the two powers, enabled Germany to invade Poland without Soviet intervention (Invasion of Poland). On September 1, 1939, Germany invaded Poland and later on September 17, 1939, the Soviet Union invaded the eastern part of the coun try. Britain and France, standing by their guarantee declared war against Germany September 3, 1939 (Invasion of Poland). This was the beginning of World War II. The Phony War was the label given to the period of time between September 1939 and 1940 when Britain and France had not fought in combat. For several months, German troops sat and waited while French forces held their defenses (The Finest Hour). The Phony War would come to an end on April 9, 1940 when Hitler began a successful attack on Denmark and Norway. Then on May 10, German troops launched a blitzkrieg attack on the Netherlands, Belgium, and Luxembourg. The German army was quickly advancing across Europe and would soon cross the line of fortifications that protected France. On June 10, 1940, Hitlers armies swept throughout the region of France with Frances defeat only a matter of time, the country fell under Nazi control on June 22 (The Finest Hour). After the fall of France, Prime Minister Churchill faced the possibility of invasion coming from France, across the English Channel. Churchill amassed the British navy to stand between Hitler and England. In an attempt to demolish the Royal navy, Hitler turned to the Luftwaffe, Germanys air force, to destroy Brittans air defenses. The intense attack called the Battle of Britain would continue for three months where day after day as many as a thousand German airplanes dropped bombs within the city of London and Britain (The Finest hour). By the end of 1941, Britain had experienced a shortage of war materials that they were unable to pay for and was fatigued by the constant air raids from the Germans. Churchill, in favor for an alliance with the U.S., tried to communicate with Roosevelt to facilitate the sending of military supplies over to Britain (The Finest hour). Bounded by the Neutrality Act of 1939, the U.S. was not permitted to release arms to any warring country unless on cash and carry terms (Decker and Chiei 2). Without antagonizing the isolationist who wanted to keep the U.S out of international affairs, Roosevelt constructed the Lend-Lease Act, a bill that empowered the president to sell, transfer title to, lend, lease, or dispose of [articles of defense to] the government of any country the President deems vital to the defense of the United States. The Lend-Lease Act provided the British with planes, tanks, guns, artillery, and ammunition without them paying for it. Bypassing the legislation would prove c ritical to sustaining U.S. allies and would be necessary for continued preparation for what appeared to be the inevitable involvement of the U.S. in WWII (Decker and Chiei 2). Throughout 1940 and 1941, Churchill attempted to win the confidence of Americans by demonstrating his trust in them. Roosevelts presidential advisors Averell Harriman and Harry Hopkins were invited by Churchill to meet Britains highest military leaders (The Finest Hour). Broad- ranging talks would consolidate policy during the meetings (Robbins). Outlining his views on strategy to win the American alliance in the war, Churchill reassured his guests that the Japanese would not enter the war until they were sure that we were beaten. They did not want to fight the United States and the British Empire together (qtd. in The Finest Hour). The roaring advance of Hitlers Nazi army had widened the war rapidly and Hitlers attack on Russia had created the need for a Roosevelt-Churchill summit meeting (Robbins). Roosevelt planned for a meeting between the two leaders that was privately held off the coast of Newfoundland. The President objective for the meeting was to cement relations with Britai n and to discuss terms on the Lend-Lease Act. Churchills objective was to draw the U.S. into WWII and secure more help for the British (Behind Closed Doors). Boarding the British battleship HMS Prince of Wales on August 4, 1941, Churchill proceeded on his voyage to meet with the President. Cruising through malignant waters of the Atlantic Ocean filled with enemy submarines and raiders shrugged off the dangers and continued to toil away at official papers and increasing Roosevelts support for the war (Robbins). Churchills departure was kept at utmost secrecy to outmaneuver Hitlers Kriegsmarine. While Churchills whereabouts were kept hidden, however, because the Americans were still at peace, presidential locations were fully located. The White House told the nation that Roosevelt was enjoying a fishing holiday onboard the Presidential yacht Potomac. Once Roosevelt left the surveillance of the nation, he joined the U.S.S Augusta and continued his voyage to Placentia Bay under the shield of planes and destroyers (Robbins). The destiny of the world would depend on the effectiveness of the policies agreed by Winston and Churchill. After the attack on Russia by the Germans on June 22, 1941, Churchill immediately aligned with the Russians and arranged the signing of a pact to provide possible aid. On August 9, 1941, Churchill met Roosevelt onboard the U.S.S. Augusta, anchored off the coast of Newfoundland in Placentia Bay. This would mark the beginning of high-level collaborations that would continue until the end of the war (The Finest Hour). During the meeting at Newfoundland, there was a discussion on a strategy to block the anticipated military moves of Hitler and Mussolini. Those present at the meeting felt that combined American and British staff had enough to outwit the axis dictators, though a round table alliance was scarcely the type of structure Hitler was likely to employ with Rome and Tokyo (Robbins). Future moves for the war were coordinated at the meeting to ensure that Hitlers despotism was destroyed. The issue of the Far East and Japan had to be taken care of, also including the issue of Vichy France and the best means of keeping the French battleships out of German hands (Robbins). The stature of the meeting was manifest in the way the two leaders came together for Sunday service on the battleship Prince of Wales. A symbolic moment at war took place when military leaders and sailors of both nations mingles together to sing hymns that Churchill had selected (The finest Hour). On the last day of the meeting Roosevelt and Churchill issued the Atlantic Charter, which expressed a commitment to the principles of self governance and freedom for every country, called for the destruction of the Nazi tyranny, and looked forward to free trade, cooperation, and peace among all nations. The post-war goals the leaders discussed became points laid out in the charter that were for the betterment of the world: (1) Countries shall not seek territorial gain, (2) If the citizens or governing government do not approve of territorial gain, then there shall be none, (3) The rights of people should be respected and not deprived from them, (4) Economic prosperity and trade should Endeavour between the two countries, (5) Collaboration between nations of improved labor standards, economic prosperity, and social security, (6) After WWII, hopes to see established worldwide peace and people have the freedom of speech, (7) If such peace is achieved, then people should be able to be fr ee to move around the world without intervention, (8) All the nations of the world should abandon the use of weapons. (Atlantic Charter). In London September 24, 1941, the delegate of the ten allied nations including the Soviet Union proclaimed allegiance to the Atlantic Charter. U.S. neutrality ended December 7, 1941 when Japan attacked Pearl Harbor. Hitler declared war and the U.S. inevitably entered WWII, along with its allies Britain and Russia. During WWII, although Roosevelt, Churchill, and Stalin were allies, tensions arose between the great three leaders. The glue that held the Anglo-American-Soviet alliance together during the war was the determination to defeat Nazi Germany, fascist Italy, and Japans military government reaching for control of East Asia (Uneasy Allies). The leaders held discreet aims for their respective countries that were in conflict with each other, though by temporary muting their differences they allowed their alliance to survive. Debate arose concerning from the first point of the Atlantic Charter; Countries shall not seek territorial gain. A key issue was Roosevelts mistrust of Britains imperial ambitions. The question was asked Would Britain give up its Nations of Commonwealth in order to comply with the standard of the charter?. Britain had imperialistic motives and Roosevelt did not agree with them, he saw the charter as a solution to end it (BBC). Declarations two and four of the charter lai d the foundations for granting of independence to Britains colonial empire which began as early as 1947. Meanwhile another territorial issue was brewing with one of the Allies. Stalins ideological post-war degrees about control over nations increased tensions between himself and Churchill. At the Teheran meeting, Churchill and Stalin made percentage agreements over how much each nation school control Europe. An agreement was never reached and this has proved to have cause strained tensions against the Soviet Union for attempting to spread communist rule around Eastern Europe (Uneasy Allies). Today, we see proof of the Atlantic Charters lasting impact when people of free nations try and collaborate to try to rescue those victimized by tyrants. The goals laid out by President Roosevelt and Winston Churchill at that diplomatic meeting in August 1941 has laid the foundation of peacekeeping organizations, that strive to keep at equal human rights. Organizations such as the U.N and NATO have sprung from the principles of the charter, created nearly six decades ago, its intent still worthwhile today. The alliance forged at Placentia Bay between two great leaders would prove to be successful in defeating the Nazi Regime and keeping worldwide peace.

Sport, Education, and the Meaning of Victory Essay -- Athletics Greece

Sport, Education, and the Meaning of Victory Sport was included in ancient educational systems because it was thought to promote aretà ª or human excellence which could be applied to almost any endeavor in life. The goal of most modern scholastic athletic programs might be better summed up in a word: winning. Is this a sign that we have lost touch with the age-old rationale for including sport in education? I argue that it need not be by showing that we value winning precisely for the virtues associated with it. I then take Plato's traditional parts of aretà ª: piety, sophrosunà ª, courage and justice and show how they are manifest in modern athletic ideals of self-knowledge, discipline, courage and justice. To the extent that scholastic athletic programs develop these virtues, I conclude, their pursuit of winning is not at odds with the institutional mission of educating students. If an athletic program's pursuit of victory allows such character-building to fall by the wayside, however, it deserves no place in our high scho ols, colleges or universities. As in the world of the Ancient Greeks, sport plays an important role in the educational institutions of 20th century America. The reasoning for this in ancient times, as now, is a belief that sport helps to make better people — that it promotes excellence (what the Greeks called aretà ª) in individuals, excellence which can be applied to almost any endeavor in life. That said, it must be acknowledged that most athletes, coaches, and school administrations identify the goal of their athletic programs in one word: winning. Is this a sign that we've lost touch with the age-old rationale for including sport in education? Is the philosophy that "winning is everything," or "the only thing... .... 38-45. Marrou, H. I. 1956. A History of Education in Antiquity, translated by George Lamb. Madison, WI: University of Wisconsin Press. Mihalich, Joseph. 1992. Sports and Athletics: Philosophy in Action. Totowa, NJ: Rowman and Littlefield. Nettleship, R. L. 1935. The Theory of Education in Plato's Republic. London: Oxford University Press. First published in Hellenica in 1880. Plato. 1989. Collected Dialogues. Edited by Edith Hamilton and Huntington Cairns. Princeton, NJ: Princeton University Press. Sansone, David. 1988. Greek Athletics and the Genesis of Sport. Berkeley, CA: University of California Press. Simon, Robert L. 1984. "Good Competition and Drug-Enhanced Performance." Journal of the Philosophy of Sport, vol. XI. 6-13. Walton, Gary M. 1992. Beyond Winning: The Timeless Wisdom of Great Philosopher Coaches. Champaign, IL: Leisure Press.

Reducing Symptoms in Bulimia Nervosa and Binge Eating Disorder Through

Reducing Symptoms in Bulimia Nervosa and Binge Eating Disorder Through Drug Treatment Bulimia nervosa is a chronic psychiatric disorder that haunts the lives of many young women. The disorder is characterized by frequent episodes of binge eating followed by some sort of purging. The purging usually involves self-induced vomiting and can cause great damage to the body. Persons diagnosed with bulimia nervosa have a loss of control over these behaviors. Affecting the lives of 3-5% of young women, bulimia is a problem that is spinning out of control and nothing seems to be able to stop it. Binge eating disorder is another psychiatric disease that causes problems for many people. In this disorder, persons binge frequently but do not attempt to compensate for their eating by using purging techniques such as those used by persons suffering from bulimia nervosa. There are many types of treatments that attempt to mitigate the symptoms of bulimia and binge eating disorder. But what causes the binges in binge eating disorder and what causes the binge-purge cycle in bulimics? How can the symptoms of these disorders be reduced or eliminated? If the causes of these behaviors are discovered, the behaviors can be reduced. There are several therapies that have proven to be fairly effective in treating persons diagnosed with bulimia nervosa. Drug therapy has made great advances in recent years and goes straight to the root of the problem. Drug therapy attempts to uncover the biological causes of the symptoms of bulimia nervosa and binge eating disorder. A discovery made recently found that there is an inverse correlation among women with bulimia between the frequency of binge-eating and cerebrospinal fluid concentration of the major ser... ...very effective. This manual should be researched and developed further because not only can people educate themselves, but therapists can have more time to focus on deeper problems and on patients who do not respond well to such therapies. Works Cited Hartman, Boyd K., Faris, Patricia L. Treatment of Bulimia Nervosa With Odansetron. Archives of General Psychiatry. 1997; 54: 969-970. Hudson, James I., McElroy, Susan L. Fluvoxamine in the Treatment of Binge-Eating Disorder. The American Journal of Psychiatry. 1998; 155: 1756-1762. Rissanen, Aila., Naukkarinen, Hannu. Fluoxetine Normalizes Increased Cardiac Vagal Tone in Bulimia Nervosa. Journal of Clinical Psychopharmacology. 1998; 18: 26-32. Treasure, Janet., Schmidt, Ulrike. Sequential Treatment for Bulimia Nervosa Incorporating a Self-Care Manual. The British Journal of Psychiatry. 1996; 168: 94-98.

Essay on Names in Song of Solomon -- Song Solomon essays

The Importance of Names in Song of Solomon      Ã‚   Abstract:   In Toni Morrison's Song of Solomon, names have great implication.   Language is extremely personal and deeply rooted in culture.   Names are an integral part of language, and they help to establish identity, define personality, and show ownership through formal and informal usage.    " 'Tis but thy name that is my enemy; / Thou art thyself, though not a Montague. / What's Montague? it is nor hand, nor foot, / Nor arm, nor face, nor any other part / Belonging to a man.   O, be some other name! / What's in a name? that which we call a rose / By any other name would smell as sweet; / So Romeo would, were he not Romeo call'd, / Retain that dear perfection which he owes / Without that title.   Romeo, doff thy name, / And for that name which is no part of thee / Take all myself."   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   -William Shakespeare, Romeo and Juliet.      Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   In the play Romeo and Juliet, William Shakespeare claims that a name is just a name; that it has no real significance.   Individual names and the names of cultural and racial groups can be very influential, however, as Malcolm X explains in his On Afro-American History, "So they'll say whites, Puerto Ricans and Negroes.   Pick up on that.   That's a drag, brothers.   White is legitimate.   It means what color they are.   Puerto Ricans tell you that they're something else, came from somewhere else, but they're here now.   Negro doesn't tell you anything" (16).   In Toni Morrison's Song of Solomon, which describes the tribulations faced by an African American family attempting to define and find themselves, names have great implication.   Language is extremely personal and deeply rooted in culture.   Names are an integral part... ...d many important lessons about his past as well.   It was possible to see the transformation from materialistic to concerned that Milkman underwent.   By coming to terms with his roots, Milkman was able to become whole; to become comfortable with who and what he was.   Knowledge is power, and having a name and a history are two of the most powerful things one could have.  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚     Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   Works Cited and Consulted Bloom, Harold, ed. Modern Critical Views: Toni Morrison. New York: Chelsea House Publishing, 1990. Malcolm X.   "On Afro-American History."   Audubon Ballroom, Harlem.   24 Jan 1965. Middleton, David. Toni Morrison's Fiction: Contemporary Criticism. New York: Garland, 1997. Morrison, Toni.   Song of Solomon.   New York: Plume, 1987.   Shakespeare, William. Romeo & Juliet. ed. Jane Backman. Lincolnwood: NTC Publishing Group, 1994.

Hot Wet Equatorial Climate

THE HOT, WET EQUATORIAL CLIMATE Distribution -Is found between 5 ° and 10 °N and S of the equator. Its greatest extent is found in the lowlands of the Amazon, Congo D. R, Malaysia and the East Indies. -Further away from the equator, the influence on the on-shore Trade Winds gives rise to a modified type of equatorial climate with the Monsoon influences. -Within the tropics, the equatorial highlands have a distinctively cooler climate, modified by altitude such as the Cameron highlands, northern Andes and Kenyan highlands in East AfricaMap CLIMATE 1. Temperature – The most outstanding feature of an equatorial climate is its great uniformity of temperature through out the year – The mean annual temperatures are always around 27 °C with very little variation. -there is no winter. -cloudiness and precipitation help to moderate the daily temperature so that even at the equator itself the climate is bearable. -regular land and sea breezes also assist in maintaining a tr uly equable climate. -the diurnal range is small and so is the annual range.Figures below illustrate the rhythm of climate experienced in two different equatorial regions, one on lowland (Kuala Lumpur) and the other on the highland (Bogota). Kuala Lumpur Month JFMAMJJASOND Temp( °C)262627272727262626262627 Rainfall (mm)170170236279216127104157185274257231 Annual precipitation 2 413mm Annual temperature range 1 °C (27 °C – 26 °C) Bogota Month JFMAMJJASOND Temp( °C)141415151414141414141414 Rainfall (mm)948912424416581668474213224142 Annual precipitation 1 610mm Annual temperature range 1 °C (15 °C – 14 °C) 2. Rainfall – Rainfall is heavy, between 1 524mm and 2 540mm and well distributed throughout the year. There is no month without rain. There are two periods of maximum rainfall, April and October which occur shortly after the equinoxes. The double rainfall peaks coinciding with the equinoxes are a characteristic feature of equatorial climates not found in any other type of climate. -Due to great heat in the equatorial belt mornings are bright and sunny. There is much evaporation and convection air currents are set up, followed by heavy downpours of convectional rains in the afternoon from the towering cumulonimbus clouds. -Besides the convectional rainfall, mountainous regions also experience much Orographic or relief rainfall.In addition, there are some intermittent showers from cyclonic atmospheric disturbances caused by the convergence of air currents in the doldrums. -The relative humidity is constantly high (over80%) making one feel sticky and uncomfortable. NATURAL VEGETATION -Equatorial region support a luxuriant type of dense vegetation –the tropical rain forest- because of heavy rainfall and uniform temperature. -In the Amazon lowlands, the forest is so dense and so complete that a special term ‘Selvas’ is used. 1. A great variety of vegetation -The equatorial vegetation comprises a multitude of evergreen trees that yield tropical hardwood e. . mahogany, ebony, greenheart, cabinet woods and dyewoods. -There are smaller palm trees, climbing plants like lianas or rattan which may be hundred of metres long and epiphytic and parasitic plants that live on other plants. -Under the trees grow a wide variety of creepers, ferns, orchids and lalang 2. A distinct layer arrangement .-From the air, the tropical rain forest appears like a thick canopy of foliage. All plants struggle upwards for sunlight resulting in a peculiar later arrangement. -The tallest trees attain a height of 45m with dense undergrowth that can tolerate shade. 3. Multiple species Trees of equatorial rainforest are not found in pure stands of a single species like in the temperate where forests where only a few species occur in a particular area. This has made timber exploitation to be difficult. 4. Forest clearings -Many parts of the virgin tropical rainforests have been cleared either for lumbering or shifting c ultivation. When these clearings are abandoned, less luxuriant secondary forests, called belukar in Malaysia, spring up. -These are characterised by short trees and very dense undergrowth. Mangrove forests thrive in the coastal areas and brackish swamps. LIFE AND DEVELOPMENTThe equatorial regions are generally sparsely populated. In the forests most primitive people live as hunters and collectors and the more advanced ones practice shifting cultivation. Food is so abundant in such a habitat that many people worry very little the life of the next day. There are numerous animals, birds and reptiles and can be hunted to serve the needs of the community. Crops grown include manioc (tapioca), yams, maize, bananas and groundnuts. Plantation agriculture is also practised widely with the outstanding crop, rubber. Malaysia and Indonesia are the leading producers of rubber.Another tropical crop is cocoa, which is more extensively cultivated in West Africa in Ghana and Ivory Coast. Other crops include oil palm, cocoanuts, coffee, tea, tobacco, spices, bananas, pineapples, etc. FACTORS AFFECTING DEVELOPMENT †¢Equatorial climate and health: excessive heat and humidity expose human beings to sunstroke and to such diseases as malaria and yellow fever. †¢Prevalence of bacteria and insect pests. †¢Jungle hinders development and maintenance. †¢Rapid deterioration of tropical soil. †¢Difficulties in lumbering and live stock farming. †¢Poor pasture.

Steel Design

STEEL BEAM DESIGN Laterally Unrestrained Beam Dr. A Aziz Saim 2010 EC3 Unrestrained Beam 1 Non-dimensional slenderness Beam behaviour analogous to yielding/buckling of columns. M Wyfy Material yielding (in-plane bending) MEd MEd Elastic member buckling Mcr Lcr 1. 0 Dr. A Aziz Saim 2010 EC3 Non-dimensional slenderness Unrestrained Beam ? LT 2 Lateral torsional buckling Lateral torsional buckling Lateral torsional buckling is the member buckling mode associated with slender beams loaded about their major axis, without continuous lateral restraint.If continuous lateral restraint is provided to the beam, then lateral torsional buckling will be prevented and failure will occur in another mode, generally in-plane bending (and/or shear). Dr. A Aziz Saim 2010 EC3 Unrestrained Beam 3 Eurocode 3 Eurocode 3 states, as with BS 5950, that both crosssectional and member bending resistance must be verified: MEd ? Mc ,Rd Cross-section check (In-plane bending) MEd ? Mb,Rd Dr. A Aziz Saim 2010 EC3 Unr estrained Beam Member buckling check 4 Dr. A Aziz Saim 2010 EC3 Unrestrained Beam 5 Laterally Unrestrained BeamThe design of beam in this Lecture 3 is considering beams in which either no lateral restraint or only intermittent lateral restraint is provided to the compression flange Dr. A Aziz Saim 2010 EC3 Unrestrained Beam 6 Lateral Torsional Buckling Dr. A Aziz Saim 2010 EC3 Unrestrained Beam 7 Lateral Torsional Buckling Figure 3-1 shows an unrestrained beam subjected to load increment. The compression flange unrestrained and beam is not stiff enough. There is a tendency for the beam to deform sideways and twist about the longitudinal axis. The failure mode which may occur to the beam is called lateral torsional buckling.Dr. A Aziz Saim 2010 EC3 Unrestrained Beam 8 ?Involves both deflection and twisting rotation ?Out-of plane buckling. Bending Resistance M c, Rd ? M pl ? W pl f y ?M0 Due to the effect of LTB, the bending resistance of cross section become less. Failure may occurs earlier then expected Dr. A Aziz Saim 2010 EC3 Unrestrained Beam 9 Examples of Laterally Unrestrained Beam Dr. A Aziz Saim 2010 EC3 Unrestrained Beam 10 Restrained Beam Comparsion Dr. A Aziz Saim 2010 EC3 Unrestrained Beam 11 Intermittent Lateral Restrained Dr. A Aziz Saim 2010 EC3 Unrestrained Beam 12Torsional restraint Usually both flanges are held in their relative positions by external members during bending. May be provided by load bearing stiffeners or provision of adequate end connection details. See Figure 3-4. Dr. A Aziz Saim 2010 EC3 Unrestrained Beam 13 Beam without torsional restraint Dr. A Aziz Saim 2010 EC3 Unrestrained Beam 14 Can be discounted when: †¢ Minor axis bending †¢ CHS, SHS, circular or square bar †¢ Fully laterally restrained beams †¢ ? LT< 0. 2 (or 0. 4 in some cases) – Unrestrained length Cross-sectional shape End restrained condition The moment along the beam Loading – tension or compression Unrestrained Beam 16Dr. A Azi z Saim 2010 EC3 Lateral torsional buckling resistance Checks should be carried out on all unrestrained segments of beams (between the points where lateral restraint exists). Lateral restraint Lateral restraint Lcr = 1. 0 L Lateral restraint Beam on plan Dr. A Aziz Saim 2010 EC3 Unrestrained Beam 17 Three methods to check LTB in EC3: †¢ The primary method adopts the lateral torsional buckling curves given by equations 6. 56 and 6. 57, and is set out in clause 6. 3. 2. 2 (general case) and clause 6. 3. 2. 3 (for rolled sections and equivalent welded sections). The second is a simplified assessment method for beams with restraints in buildings, and is set out in clause 6. 3. 2. 4. †¢ The third is a general method for lateral and lateral torsional buckling of structural components, given in clause 6. 3. 4. Dr. A Aziz Saim 2010 EC3 Unrestrained Beam 18 Eurocode 3 states, as with BS 5950, that both cross-sectional and member bending resistance must be verified: MEd ? Mc ,Rd Cros s-section check (In-plane bending) MEd ? Mb,Rd Dr. A Aziz Saim 2010 EC3 Unrestrained Beam Member buckling check 19 Lateral-torsional buckling Eurocode 3 design approach for lateral torsional buckling is analogous to the olumn buckling treatment. The design buckling resistance Mb,Rd of a laterally unrestrained beam (or segment of beam) should be taken as: Mb,Rd ? ?LT Wy fy ? M1 Reduction factor for LTB Lateral torsional buckling resistance: Mb,Rd = ?LT Wy fy ? M1 Equation (6. 55) Wy will be Wpl,y or Wel,y ?LT Dr. A Aziz Saim 2010 EC3 is the reduction factor for lateral torsional buckling Unrestrained Beam 21 Buckling curves – general case (Cl 6. 3. 2. 2) Lateral torsional buckling curves for the general case are given below : (as in Eq (6. 56)) ?LT ? 1 2 ? LT ? ?LT ? ?2 LT but ? LT ? 1. 0 ?LT ? 0. 5 [ 1 ? ?LT (? LT ? 0. ) ? ?2 ] LT Plateau length Imperfection factor from Table 6. 3 Dr. A Aziz Saim 2010 EC3 Unrestrained Beam 22 Imperfection factor ? LT Imperfection factors ? LT for 4 buckling curves: (refer Table 6. 3) Buckling curve Imperfection factor ? LT a 0. 21 b 0. 34 c 0. 49 d 0. 76 Buckling curve selection For the general case, refer to Table 6. 4: Cross-section Rolled I-sections Welded Isections Limits h/b ? 2 h/b > 2 h/b ? 2 h/b > 2 – Buckling curve a b c d d Other crosssections Dr. A Aziz Saim 2010 EC3 Unrestrained Beam 24 LTB curves 4 buckling curves for LTB (a, b, c and d) 1. 2 Reduction factor ? LT . 0 0. 8 0. 6 0. 4 0. 2 0. 0 0 0. 5 1 1. 5 Curve a Curve b Curve c Curve d 2 2. 5 0. 2 Dr. A Aziz Saim 2010 EC3 Non-dimensional slenderness Unrestrained Beam ?LT 25 Dr. A Aziz Saim 2010 EC3 Unrestrained Beam 26 lateral torsional buckling slenderness ? LT Mcr ? Wy f y Mcr Elastic critical buckling moment Dr. A Aziz Saim 2010 EC3 Unrestrained Beam 27 Non-dimensional slenderness †¢ Calculate lateral torsional buckling slenderness: ? LT ? Wy f y Mcr †¢ Buckling curves as for compression (except curve a0) †¢ Wy depends on section classification †¢ Mcr is the elastic critical LTB moment Dr. A Aziz Saim 2010 EC3Unrestrained Beam 28 BS EN 1993-1-1 does not give a method for determining the elastic critical moment for lateraltorsional buckling Mcr !!!!!!!! May use ‘LTBeam’ software (can be downloaded from CTICM website) Or may use method presented by L. Gardner †¦Ã¢â‚¬ ¦. Dr. A Aziz Saim 2010 EC3 Unrestrained Beam 29 Mcr under uniform moment For typical end conditions, and under uniform moment the elastic critical lateral torsional buckling moment Mcr is: Mcr ,0 G IT Iw Iz Lcr ? EIz ? 2 Lcr 2 ? Iw Lcr GIT ? ? ? 2 ? ? EIz ? ? Iz 2 0. 5 is the shear modulus is the torsion constant is the warping constant is the inor axis second moment of area is the buckling length of the beam Unrestrained Beam 30 Dr. A Aziz Saim 2010 EC3 Mcr under non-uniform moment Numerical solutions have been calculated for a number of other loading conditions. For uniform doubly-symmetric cross-sections, loaded through the shear centre at the level of the centroidal axis, and with the standard conditions of restraint described, Mcr may be calculated by: ? EIz Mcr ? C1 2 Lcr 2 Dr. A Aziz Saim 2010 EC3 Unrestrained Beam ? Iw Lcr GIT ? ? ? 2 ? ? EIz ? ? Iz 2 0. 5 31 C1 factor – end momentsFor end moment loading C1 may be approximated by the equation below, though other approximations also exist. C1= 1. 88 – 1. 40y + 0. 52y2 but C1 ? 2. 70 where y is the ratio of the end moments (defined in the following table). Dr. A Aziz Saim 2010 EC3 Unrestrained Beam 32 C1 factor – transverse loading Loading and support conditions Bending moment diagram Value of C1 1. 132 1. 285 1. 365 1. 565 1. 046 Dr. A Aziz Saim 2010 EC3 Unrestrained Beam 33 Design procedure for LTB Design procedure for LTB: 1. Determine BMD and SFD from design loads 2. Select section and determine geometry 3. Classify cross-section (Class 1, 2, 3 or 4) 4.Determine effective (buckling) length Lcr – depends on bounda ry conditions and load level 5. Calculate Mcr and Wyfy Dr. A Aziz Saim 2010 EC3 Unrestrained Beam 34 Design procedure for LTB 6. Non-dimensional slenderness ? LT ? Wy fy Mcr 7. Determine imperfection factor ? LT 8. Calculate buckling reduction factor ? LT 9. Design buckling resistance 10. Check Mb,Rd ? ?LT Wy fy ? M1 MEd ? 1. 0 Mb,Rd for each unrestrained portion Dr. A Aziz Saim 2010 EC3 Unrestrained Beam 35 LTB Example General arrangement Dr. A Aziz Saim 2010 EC3 Unrestrained Beam 36 LTB Example Design loading is as follows: 425. 1 kN A B C 319. 6 kN D 2. 5 m 3. 2 m 5. 1 mLoading Dr. A Aziz Saim 2010 EC3 Unrestrained Beam 37 LTB Example 267. 1 kN A B D 52. 5 kN SF C 477. 6 kN Shear force diagram B A C D BM 1194 kNm 1362 kNm Bending moment diagram Dr. A Aziz Saim 2010 EC3 Unrestrained Beam 38 LTB Example For the purposes of this example, lateral torsional buckling curves for the general case will be utilised. Lateral torsional buckling checks to be carried out on segments BC and CD. By inspection, segment AB is not critical. Try 762? 267? 173 UB in grade S 275 steel. Dr. A Aziz Saim 2010 EC3 Unrestrained Beam 39 LTB Example b z tw h d y y r z tf h = 762. 2 mm b = 266. 7 mm tw = 14. 3 mm tf = 21. 6 mm r = 16. mm A = 22000 mm2 Wy,pl = 6198? 103 mm3 Iz = 68. 50? 106 mm4 It = 2670? 103 mm4 Iw = 9390? 109 mm6 Dr. A Aziz Saim 2010 EC3 Unrestrained Beam 40 LTB Example For a nominal material thickness (tf = 21. 6 mm and tw = 14. 3 mm) of between 16 mm and 40 mm the nominal values of yield strength fy for grade S 275 steel (to EN 10025-2) is 265 N/mm2. From clause 3. 2. 6: N/mm2. E = 210000 N/mm2 and G ? 81000 Dr. A Aziz Saim 2010 EC3 Unrestrained Beam 41 LTB Example Cross-section classification (clause 5. 5. 2): e ? 235 / fy ? 235 / 265 ? 0. 94 Outstand flanges (Table 5. 2, sheet 2) cf = (b – tw – 2r) / 2 = 109. 7 mm cf / tf = 109. 7 / 21. 6 = 5. 8 Limit for Class 1 flange = 9e = 8. 48 > 5. 08 ? Flange is Class 1 Dr. A Aziz Saim 2010 EC3 Unrestrained Bea m 42 LTB Example Web – internal part in bending (Table 5. 2, sheet 1) cw = h – 2tf – 2r = 686. 0 mm cw / tw= 686. 0 / 14. 3 = 48. 0 Limit for Class 1 web = 72 e = 67. 8 > 48. 0 ? Web is Class 1 Overall cross-section classification is therefore Class 1. Dr. A Aziz Saim 2010 EC3 Unrestrained Beam 43 LTB Example Bending resistance of cross-section (clause 6. 2. 5): Mc ,y,Rd ? Wpl,y fy ? M0 for Class 1 and 2 sec tions 6198 ? 103 ? 265 ? ? 1642 ? 106 Nmm 1. 0 ? 1642 kNm ? 1362 kNm ? Cross-section resistance in bending is OK.Dr. A Aziz Saim 2010 EC3 Unrestrained Beam 44 LTB Example Lateral torsional buckling check (clause 6. 3. 2. 2) – Segment BC: MEd ? 1362 kNm Mb ,Rd ? ? LT Wy fy ? M1 where Wy = Wpl,y for Class 1 and 2 sections Determine Mcr for segment BC (Lcr = 3200 mm) Dr. A Aziz Saim 2010 EC3 ? EIz Mcr ? C1 2 Lcr 2 ? Iw Lcr GIT ? ? ? 2 ? ? EIz ? ? Iz Unrestrained Beam 2 0. 5 45 LTB Example For end moment loading C1 may be approximated from: C1 = 1. 88 â⠂¬â€œ 1. 40y + 0. 52y2 but C1 ? 2. 70 1194 y is the ratio of the end moments ? ? 0. 88 1362 ? C1 ? 1. 05 ? 2 ? 210000 ? 68. 5 ? 106 Mcr ? 1. 05 ? 32002 ? 9390 ? 109 32002 ? 81000 ? 2670 ? 103 ? ? ? 68. 5 ? 106 ? 2 ? 210000 ? 68. 5 ? 106 ? ? 0. 5 = 5699Ãâ€"106 Nmm = 5699 kNm Dr. A Aziz Saim 2010 EC3 Unrestrained Beam 46 LTB Example Non-dimensional lateral torsional slenderness for segment BC: ? LT ? Wy fy Mcr 6198 ? 103 ? 265 ? ? 0. 54 6 5699 ? 10 Select buckling curve and imperfection factor ? LT: From Table 6. 4: h/b = 762. 2/266. 7 = 2. 85 For a rolled I-section with h/b > 2, use buckling curve b Dr. A Aziz Saim 2010 EC3 Unrestrained Beam 47 LTB Example From Table 6. 3 of EN 1993-1-1: For buckling curve b, ? LT = 0. 34 Calculate reduction factor for lateral torsional buckling, ? LT – Segment BC: ?LT ? 1 ? LT ? ? 2 LT LT but ? LT ? 1. 0 where ? LT ? 0. 5 [ 1 ? ?LT (? LT ? 0. 2) ? ?2 ] LT Dr. A Aziz Saim 2010 EC3 Unrestrained Beam 48 LTB Example ?LT = 0. 5[1+0. 34(0. 54-0. 2) + 0. 542] = 0. 70 ? ? LT ? 1 0. 70 ? 0. 70 ? 0. 54 2 2 ? 0. 87 Lateral torsional buckling resistance Mb,Rd – Segment BC : Mb,Rd ? ? LT Wy fy ? M1 265 ? 0. 87 ? 6198 ? 10 ? 1 . 0 3 ? 1425 ? 106 Nmm ? 1425 kNm Dr. A Aziz Saim 2010 EC3 Unrestrained Beam 49 LTB Example MEd 1362 ? ? 0. 96 ? 1. 0 ? Segment BC is OK Mb,Rd 1425 Lateral torsional buckling check (clause 6. 3. 2. 2) – Segment CD: MEd ? 1362 kNm Mb ,Rd ? ? LT Wy fy ? M1 where Wy = Wpl,y for Class 1 and 2 sectionsDetermine Mcr for segment CD (Lcr = 5100 mm) Dr. A Aziz Saim 2010 EC3 Unrestrained Beam 50 LTB Example ? EIz Mcr ? C1 2 Lcr 2 ? Iw Lcr GIT ? ? ? 2 ? Iz ? EIz ? ? 2 0. 5 Determine y from Table: 0 y is the ratio of the end moments ? ?0 1362 ? C1 ? 1. 88 ? 2 ? 210000 ? 68. 5 ? 106 Mcr ? 1. 88 51002 ? 9390 ? 109 51002 ? 81000 ? 2670 ? 103 ? ? ? ? 68. 5 ? 106 ? 2 ? 210000 ? 68. 5 ? 106 ? ? 0. 5 = 4311? 106 Nmm = 4311 kNm Dr. A Aziz Saim 2010 EC3 Unrestrained Beam 51 LTB Example Non-dimensional lateral torsio nal slenderness for segment CD: ? LT ? Wy fy Mcr 6198 ? 103 ? 265 ? ? 0. 62 6 4311? 10 The buckling curve and imperfection factor ?LT are as for segment BC. Dr. A Aziz Saim 2010 EC3 Unrestrained Beam 52 LTB Example Calculate reduction factor for lateral torsional buckling, ? LT – Segment CD: ?LT ? 1 ? LT ? ? 2 LT 2 LT but ? LT ? 1. 0 where ? LT ? 0. 5 [ 1 ? ?LT (? LT ? 0. 2) ? ?2 ] LT = 0. 5[1+0. 34(0. 62-0. 2) + 0. 622] = 0. 76 ? ? LT Dr. A Aziz Saim 2010 EC3 ? 1 0. 76 ? 0. 76 ? 0. 62 2 Unrestrained Beam 2 ? 0. 83 53 LTB Example Lateral torsional buckling resistance Mb,Rd – Segment CD : Mb,Rd ? ?LT Wy fy ? M1 265 ? 0. 83 ? 6198 ? 10 ? 1. 0 3 ? 1360 ? 106 Nmm ? 1360 kNm MEd 1362 ? ? 1. 00 Mb,Rd 1360 Segment CD is critical and marginally fails LTB check.Dr. A Aziz Saim 2010 EC3 Unrestrained Beam 54 Blank Page Dr. A Aziz Saim 2010 EC3 Unrestrained Beam 55 Simplified assessment of ? LT For hot-rolled doubly symmetric I and H sections without destabilising loads,? may be conservatively simplified to: LT ? LT ? 1 0. 9 ? z ? C1 ?z 1 0. 9 ? 1 C1 E ? z ? L / iz ; ? 1 ? ? fy As a further simplification, C1 may also be conservatively taken = 1. 0. Simplified assessment of ? LT Substituting in numerical values for simplified expressions result. ? 1 , the following S235 ? LT ? 1 L / iz C1 104 S275 ? LT ? 1 L / iz C1 96 S355 ? LT ? 1 L / iz C1 85 C1 may be conservatively taken = 1. , though the level of conservatism increases the more the actual bending moment diagram differs from uniform moment. Simplified method (Cl. 6. 3. 2. 4) Simplified method for beams with restraints in buildings (Clause 6. 3. 2. 4) This method treats the compression flange of the beam and part of the web as a strut: b b Compression h Tension Compression flange + 1/3 of the compressed area of web Strut Dr. A Aziz Saim 2010 EC3 Beam Unrestrained Beam 58 General method (Cl. 6. 3. 4) General method for lateral and lateral torsional buckling of structural components †¢ May be applied to single members, plane frames etc. Requires determination of plastic and elastic (buckling) resistance of structure, which subsequently defines global slenderness †¢ Generally requires FE Dr. A Aziz Saim 2010 EC3 Unrestrained Beam 59 Blank Page Dr. A Aziz Saim 2010 EC3 Unrestrained Beam 60 Important Notes: (End Connections) When full torsional restraint exist: -both the compression and tension flanges are fully restrained against rotation on plan -both flanges are partially restrained against rotation on plan – both flanges are free to rotate on plan Unrestrained Beam 61 Dr. A Aziz Saim 2010 EC3 Connection DetailDr. A Aziz Saim 2010 EC3 Unrestrained Beam 62 Important Notes: (End Connections) Dr. A Aziz Saim 2010 EC3 Unrestrained Beam 63 Important Notes: (End Connections) When both flanges are free to rotate on plan and the compression flange is unrestrained: i. torsional restraint is provided solely by connection of the tension flange to the supports, ii. torsional re straint is provided solely by dead bearing of the tension flange on support. Unrestrained Beam 64 Dr. A Aziz Saim 2010 EC3 Dr. A Aziz Saim 2010 EC3 Unrestrained Beam 65 Dr. A Aziz Saim 2010 EC3 Unrestrained Beam 66